Abstract

Since the early 1980s the Food and Agriculture Organization of the United Nations (FAO) and the International Institute for Applied Systems Analysis (IIASA) have been collaborating on expanding FAO's Agro-ecological Zones (AEZ) methodology of land-resources appraisal by incorporating decision support tools for optimizing the use of land resources. Initially, these tools consisted of the application of linear optimization techniques for analyzing land-use scenarios with regard to single objective functions, such as maximizing agricultural production or minimizing the cost of production under specific physical environmental and socioeconomic conditions and constraints. Often, the specification of an objective function does not adequately reflect the preferences of decision-makers, which are of a multiobjective nature in many practical problems dealing with resources. Multicriteria optimization approaches address problem definitions and solutions in a more realistic way, and have recently been applied by FAO and IIASA in a land resources appraisal study in Kenya. In this study, optimization techniques coupled with multicriteria decision analysis (MCDA) techniques, using the Aspiration-Reservation Based Decision Support (ARBDS) approach, have been used to analyze various land-use scenarios, considering simultaneously several objectives such as maximizing revenues from crop and livestock production, maximizing district self-reliance in agricultural production, minimizing costs of production, and reducing environmental damage by erosion. The users of the new tool, which combines AEZ and MCDA, are expected to be natural-resources analysts and managers, land-use planners, ecologists, environmentalists, economists at national and regional levels, and agricultural extensionists at the local level.